The present invention is directed to the field of wireless Local Area Network (WLAN) technology, particularly diagnostic devices for improving WLAN operation. A WLAN operating under the IEEE 802.11a protocol communicates in the unlicensed 5 GHz frequency band. Most WLANs also operate in the 2.4 GHz band under the IEEE 802.11b protocol. Therefore, many things can interfere with their operation, including microwaves, 2.4 GHz cordless phones, Bluetooth wireless devices, etc.
An exemplary WLAN configuration is shown in FIG. 1. One or more access points 12 (or APs) are hardwired into a network backbone 14 and communicate wirelessly with a number of wireless clients 16, which can be desktop or laptop computers, handheld units, tablet interfaces, etc. When installing indoor and outdoor 802.11 WLANs, other problems are often encountered with signal reception. Interior walls and pillars, particularly metal structural members can block and/or reduce the strength of transmission signals and thus data transfer rate, in addition to interference from other wireless devices. Other problems result from multi-path interference and echoing. Site surveys are typically performed before installing the WLAN. These surveys are typically performed with a large mobile laptop computer operating with readily-available “packet sniffing” software. However, these devices provide more “computing power” than is necessary for the task, and thus consume much energy, resulting in a short battery life. Also, troubleshooting a WLAN installation typically involves arbitrarily moving around access points 12, AP antennas and/or clients 16, until the transmission strength and data rate is observed to improve. Such a “trial and error” method is not efficient and can add considerably to the time and expense of installing a WLAN.
Other problems can be encountered with existing WLAN installations. As seen in FIG. 2, there may be “holes” or “gaps” 20 in an existing WLAN, regions within a service area that are out of range of AP transmission and reception. It can be difficult to identify and pinpoint such gaps 20, or to determine optimum placement of new APs 12 that would supply service to these regions with minimum interference to other WLAN wireless devices. In addition, it is difficult to identify specific APs 12 and clients 16 that may be transmitting and receiving in a particular location within a WLAN. Consequently, it is difficult to independently evaluate the quality of a wireless connection. Conversely, since 802.11 WLANs operate in the unlicensed 2.4 GHz and 5.0 GHz frequency bands, it is possible to violate the security of the WLAN and gain access, particularly if no security protocols are in place.